The objectives of the proposed work are to perform biochemical and mechanism of action studies of known and new anticancer agents in four different mouse colon tumors and in normal colon tissue. At the present time 5-fluorouracil and certain nitrosoureas are among agents used clinically in chemotherapy of human colon cancer. The need for better agents and for combinations of agents in the treatment of colon cancer is generally recognized. Knowledge gained from biochemical studies of these agents and of congeners and analogs of these agents as well as of new agents will be used to design combinations of agents. Observation of differential response, and differential rates of recovery of biochemical function, such as macromolecular synthesis, in normal and tumor tissue, after treatment with single agents or combinations of agents, provides a basis for planning chemotherapy experiments in collaboration with members of our Chemotherapy Department.